Sierra Water Pump Plate 18-3357 for Yamaha 2 HP Outboards

The Sierra 18-3357 is a water pump plate designed as a replacement component within the water pump assembly of Yamaha 2 HP outboard motors. This plate sits within the lower unit water pump housing and works alongside the impeller, cup, and seal to maintain proper water flow for engine cooling. Keeping this plate in good condition, along with the rest of the water pump components, helps ensure the impeller seats and seals correctly against the housing so the pump can draw and circulate cooling water as intended.

This plate is identified by Sierra part number 18-3357 and is built to fit Yamaha 2 HP outboards from the 1984-87 and 1988-02 model years. It is a lightweight component at 0.03 pounds, sized specifically for the water pump assembly on these outboards. When servicing a water pump on a compatible Yamaha 2 HP motor, this plate is typically replaced together with the associated impeller, cup, and seal to restore full cooling performance.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3357
• Component Type: Water Pump Plate
• Weight: 0.03 pounds
• UPC: 808282226701
• Fitment: Yamaha 2 HP outboards, 1984-87 and 1988-02

Fitment

• Yamaha 2 HP outboards, model years 1984-87
• Yamaha 2 HP outboards, model years 1988-02

Frequently Asked Questions

What is the Sierra 18-3357 plate used for? The Sierra 18-3357 is a water pump plate that fits within the water pump assembly of Yamaha 2 HP outboards, working with the impeller, cup, and seal to support proper cooling water circulation.

Which outboards does the 18-3357 plate fit? This plate fits Yamaha 2 HP outboards from the 1984-87 model years as well as Yamaha 2 HP outboards from the 1988-02 model years.

Does the 18-3357 plate fit Yamaha outboards other than the 2 HP model? No, the 18-3357 plate is specified for Yamaha 2 HP outboards only, covering the 1984-87 and 1988-02 model years.

How much does the 18-3357 water pump plate weigh? The Sierra 18-3357 water pump plate weighs 0.03 pounds.

Should the water pump plate be replaced along with the impeller? Yes, when servicing the water pump on a compatible Yamaha 2 HP outboard, the 18-3357 plate is typically replaced together with the impeller, cup, and seal to restore full cooling performance.

Is the 18-3357 a Sierra part number or an OEM Yamaha number? 18-3357 is the Sierra part number used to identify this water pump plate for Yamaha 2 HP outboards.

Does the 18-3357 plate come with a full water pump kit? No, the 18-3357 is the individual plate component; it is sold on its own and is not the same as a complete water pump kit.

What does the water pump plate do inside the pump housing? Within the water pump housing on a Yamaha 2 HP outboard, the 18-3357 plate helps the impeller and related components seat and seal properly so the pump can draw and circulate cooling water.

Is the Sierra 18-3357 a genuine Sierra part? Yes, the 18-3357 water pump plate is a Sierra-branded marine part made for Yamaha 2 HP outboard water pump service.

How do I know if my Yamaha 2 HP outboard needs this plate replaced? If the water pump on a Yamaha 2 HP outboard (1984-87 or 1988-02) is being serviced due to reduced cooling water flow, the plate, along with the impeller, cup, and seal, should be inspected and replaced as part of the repair.